Method and apparatus for positioning strip



April 15, 1952 E. 'r. LORIG METHOD AND APPARATUS FOR POSITIONING STRIPFiled Jan. 13, 1950 I 5 Sheets-Sheet 1 INVENTOR EDWIN T. LORIG ATTORNEYApril 15, 1952 E. r. LORIG 2,592,581

METHOD AND APPARATUS FOR POSITIONING STRIP 3O :E lE;5 :EILEI E INVENTOREDWIN T. LORIG ATTORNEY April 5 952 E, T. LORIG 2,592,581

METHOD AND APPARATUS FOR POSITIONING STRIP Filed Jan. 13, 1950 5Sheets-Sheet 3 ATTORNEY Patented Apr. 15, 1952 METHOD AND APPARATUS FORPOSITIONING STRIP Edwin T. Lorig, Ross Township, Allegheny County, Pa.,assignor to United States Steel Company, a corporation of New JerseyApplication January 13, 1950, Serial No. 138,389

13 Claims.

This invention relates to a method of and apparatus for automaticallycentering and aligning moving objects, especially strip and striplikematerials. In the processing of metal strip, the strip is conveyed overrolls in the uncoiled condition. When the strip is conveyed over a rollto the processing equipment it is likely that the strip will be fed at aslight angle to the roll. Because of this, the strip will work its wayacross the face of the roll. In addition, the camber and/or lateralcurvature which is present in the finished strip due to rollingdifiiculties causes the strip to approach the roll at an angle, thisalso causing the strip to move across the face of the roll. In order tokeep the strip in the desired path of travel, various expedients havebeen resorted to. One of the most common is the use of stationary orrotatable side guides against which the edges of the strip bear. In someinstances side guides have been used in conjunction with looper pits toforce the strip back on the desired center line. The use of abnormallyhigh strip tension has been tried in an attempt to keep the stripaligned. Another method of operation is to periodically slip or slue thestrip back into its approximate proper position on the conveying roll.All of the above methods of centering strip tend to abrade and mutilatethe strip edges and in some instances cause the edges of the strip to bestretched beyond the elastic limit of the metal. Diagonal or lateralsurface scratches are also formed on finely finished fiat products ofall kinds, these scratches being detrimental to subsequent operationsand together with edge damage result in the scrapping of a largepercentage of the material being processed. The problems discussed abovealso exist in belt conveyors and drive belts used in conjunction withbelt pulleys. If the belt is made of rubber or other relatively softmaterial, it is more easily damaged. In addition to the methods ofaligning strip mentioned above, crown rolls have been used to centermaterials having a low modulus of elasticity such as textiles, rubberand composition belts.

One type of apparatus for centering and aligning strip is shown in mycopending application Serial No. 97,218, filed June 4, 1949.

It is an object of the present invention to provide apparatus forautomatically centering moving objects without damage thereto.

Another object is to provide such apparatus which does not depend uponcontact with the edge of the strip or abnormal tensioning of the stripto keep the strip in center alignment.

A further object is to provide a method of keeping the longitudinal axisof a moving strip in a constant vertical plane.

These and other objects will be more apparent after referring to thefollowing description and attached drawings, in which:

Figure l is a sectional view of one specific embodiment of my device;

Figure 2 is a sectional view taken on the line II-II of Figure 1;

Figure 3 is a fragmentary view, similar to Figure 1. showing a slightmodification of my device;

Figure 4. is a sectional view showing another modification;

Figure 5 is a sectional view showing a further modification;

Figure 6 is a sectional view taken on line VI- VI of Figure 5;

Figure '7 is a view, partly in section, of still another modification;

Figure 8 is a sectional view taken on line VIII-V111 of Figure 7;

Figure 9 is a sectional view of a pair of pinch rolls embodying myinvention; and

Figure 10 is an end elevation of the rolls of Figure 9.

Referring more particularly to Figures 1 and 2 of the drawings, thereference numeral 2 indicates a rotatable roll over which a strip orstriplike material S, such as a conveyor belt, passes. The roll isprovided with a plurality of flexible projections 4 and 6 which areinclined radially downward toward the axis of the roll away from thetransverse center of the roll. The roll 2 has a shaft 8 on which ismounted a sleeve It] made of rubber, neoprene, leather, fabric, or otherresilient material. The projections 4 and 6 are provided on the sleeveH) by means of slots I2 which extend circumferentially around theperiphery of the roll. If it is desired to have a smooth surface on theperiphery of the roll, the slots l2 may be filled with a material I4,such as sponge rubber, having a much greater elasticity than theprojections. The roll may be cylindrical, concave or convex as desiredto suit various installations. The projections 4 and 6 preferably arearranged at an angle between 45 and to the axis of the roll. The rollshaft 8 is supported by means of bearings l6 arranged in housing I8. Ifit is desired to drive the roll, an extension 20 can be provided at oneend of the shaft 8. A thrust ring 22 is provided between each end of thesleeve Ill and the adjacent bearing I6. When the strip S passes over theroll surface it bends the projections 4 and 6 inwardly toward the centerof the roll as shown in Figure 1. As long as the strip is centered onthe roll and the bearing pressure of the strip on the roll is uniformover its full width, no lateral movement of the strip will occur when itis conveyed over the roll. If, however, the strip is off-center or thestrip contact pressure is nonuniformffromside to .side, the projections4 .or .6 having the greatest total area in contact with the strip andthe greatest total pressure will force the strip toward the center. Inother words, as shown in Figure 1, if more of thestripis ,to the rightof the transverse center line of the roll, the projections 6 will have agreater area in contact with the strip and will forcethestrip :totheleftuntil the strip centers itself. In certain'applioations there will beonly line contact between the roll and the objects passing thereover.Inother instances, such as shown in Figure 2, the strip S may lead ontothe centering roll at pointl-24 and leave the roll at point 26. The rollmay be either -aidr-iven oranidlerrroll and'P2 is :greater thanPl. Inthis example, the :pressure of the strip S against 'therol'l surfacewill gradually increase between zjpoint 2 4 and a point F2 8 and:decrease between points 28 and: 2'6. .The shape-ofithe groove inthesrolls sis-immaterial as-long :as the projections 4 and 6 areinclined-as:setforthabove.

Figure 4- shows a .second; embodiment of my invention in which the rollis made up of a plurality .of resilient discs 3.0;mounted on :a threadedshaft .32. :The discsfisiicmayibemade of the same material as sleeve H)or they may be made from metalii .theyuare sufiicientlyfiexible to bendunder pressure. The discs 36 are inclined radially I"away-fromthe2shaft32 toward the center line of the roll. Spacers 33 areprovided between the disos -withta centericlip or none 34 :beingprovided on the transverse center of the roll between the -twocenteridiscs. An 'end clip 36 on each end of the shaft is held againstthe end discs .39 by meansofa nut '38 which is threaded on the shaft 32,thus holding the discs-39 in assembled .position.

Figures 5 and 6 showxanother embodiment of my invention:in which theprojections 4 and (Bare knobs 40 arranged in spaced apart relationshipboth longitudinally and circumferentially of the roll. The knobs 49 areformed in a sleeve 42 --mountedon a shaft.

Figures '7 and 8 show a further modification in which the projections 4and 6 are formed by pro- "-viding holes 46 in the outer periphery of theroll. 'T-hese "holes extend radially downwardly toward the axis'of theroll away from the transverse center of the roll.

In eachtof' the embodiments, the space between the projections-maybe'filled with sponge rubber or'other highly'elastic material in thesame mannerzas shown in Figure-3. Also, if desired, the outenperipheryof the rolls may be grooved longitudinally'tosecure greater resilienceon the surface. v:"Ihis is shown at 48 in Figures '7 and 8. In

allpinstances,thefunctioning of the roll i the psarnezasthat describedfor'Figure 1.

It will be .nnderstoodthat. the term transversecenter line asnsedin'theclaims of the specification is not rlimitedto. the exact geometricalcenter of the roll 'sincethe functioning of theroll will be the sameregardless of whether there are a greater number of'projections 4:01 agreater number of projectionsfi. In each instance, the strip S will becentered at. a. point between the projections 4 and 6.

.In some instances it may be desired to transfer theobject beingconveyed across the surfac of :thezrolland discharge it from one endthereof.

Lil

projections 4 and 6 are mounted .on a resilient member 50, which isprovided with an'air pocket 52 therein. The member 50 is mounted on ashaft 54 and, if desired, rigid rims 56 may b provided on .the shaft 54one on each side of the sleeve :50. This construction, which isparticularly adapted for pinch rolls, enables the contact :distance 58between the rolls to be increased, thus assisting in holding the strip Sin alignment 'while rotating 'the'rolls.

While several embodiments of my invention have been shown and described,it will be apparent that other adaptations and modifications may be madewithout departing from the scope .of thefollowing claims.

I claim:

1. Apparatus for automatically centering a moving object comprising arotatable roll over which the object passes, said .roll having aplurality of flexible projections on its outer periphery arranged onboth sides of a transverse central plane, said projections beingundercut and inclined radially toward the axis of the roll away from thesaid transverse central plane.

2. Apparatus for automatically centering a moving object according toclaim 1 in which the projections are formed by :meansof slots "extending.circumferentially around the periphery of'the. roll.

13. Apparatus .for automatically centering a moving object according toclaim 1 in which the projections are formed by means of a rollshaft,resilient discs-mounted in'spaced apart relationship on said shaft, said:discs being inclined radially away from said shaft toward .thesaidtransverse centralplane, and'means for holding said discs .on saidshaft.

4. Apparatus for automatically centering a movingobje'ctaccording toclaim 1 in which the projections are formedu'by means of a roll shaft,

resilient discs mounted in spaced apart relationshipon said shaft, said.discsbeing inclined radially away from said shaft toward the saidtransverse'central plane, spacers on said shaft between the discs,'anend clip on eachen'd of the shaft bearing against the end discs, andmean for holding said end clips firmly against the end discs.

5. Apparatus for automatically centering a moving object according toclaim 1 in which the projections are formed by means of holes extendingfrom the outer'periphery of the roll radially toward the 'axis'of' theroll'away from the said transverse central plane.

inclined radially toward the axisof the roll away from the saidtransverse central plane, the space 75 between the projections beingfilled with a mate- 5 rial having much greater elasticity than theprojections.

8. Apparatus for automatically centering a moving object according toclaim 7 in which the projections are formed by means of slots extendingcircumferentially around the periphery of the roll.

9. Apparatus for automatically centering a moving object according toclaim 7 in which the projections are formed by means of a roll shaft,resilient discs mounted in spaced apart relationship on said shaft, saiddiscs being inclined radially away from said shaft toward the saidtransverse central plane, and means for holding said discs on saidshaft.

10. Apparatus for automatically centering a moving object according toclaim 7 in which the projections are formed by means of a roll shaft,resilient discs mounted in spaced apart relationship on said shaft, saiddiscs being inclined radially away from said shaft toward the saidtransverse central plane, spacers on said shaft between the discs, anend clip on each end of the shaft bearing against the end discs, andmeans for holding said end clips firmly against the end discs.

11. Apparatus for automatically centering a moving object according toclaim 7 in which the projections are formed by means of holes extendingfrom the outer periphery of the roll radially toward the axis of theroll and away from the said transverse central plane.

12. Apparatus for automatically centering a moving object according toclaim 7 in which the roll comprises a shaft, and a resilient memberhaving an air pocket therein mounted on said shaft, said projectionsbeing supported on said resilient member.

13. A method of keeping the longitudinal axis of a moving strip in aconstant vertical plane which comprises pulling the strip over a rollhaving a plurality of flexible undercut projections on its outerperiphery inclined radially toward the axis of the roll away from thesaid vertical plane, and applying sufiicient tension to the strip todeflect the projection in contact therewith toward the axis of the roll.

EDWIN T. LORIG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,337,530 Page Apr. 30, 19201,678,925 Tackaberry July 31, 1928 2,190,740 Swift et al Feb. 20, 19402,271,166 Weiss Jan. 27, 1942 2,287,768 Eckstein June 30, 1942 2,324,050Shelle July 13, 1943 2,474,717 Belcher June 28,1949

